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<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <script type="module">
    import { reactive, computed } from './reactivity/index.js'  

    
    const product = reactive({
      name: 'iPhone',
      price: 5000,
      count: 3
    })    

    let total = computed(() => {
      return product.price * product.count
    })
        
    
    console.log(total.value)

    product.price = 4000
    console.log(total.value)

    product.count = 1
    console.log(total.value)
  </script>

</body>

</html>